I am new to the forum but I can't find a post directly related to this - our '04 Hurricane has had a sewer smell at times that seems to be coming from below (as opposed to above from vent) and today, after filling and flushing the toilet several times to top off the tank I had water (I think!) dripping on the ground from the top area of the blackwater tank. Would a bad closet flange or a faulty connector between the toilet and tank cause this? There appears to be no water or leakage inside the bathroom area. Any ideas would be appreciated

Are you sure it is a sewer odor? Gray water smells different but often confused with sewer odor?
Yes the water inlet on the commode can leak and run down the pipe to the top of the black tank, but this is clean water and should not have a foul odor. Wrap a paper towel around the pipe where it enters the floor to see if moisture is observed after a couple hours of use.
I actually have to unbolt my commode and lift it off the seal to get to my water valve and tighten it.
If it is gray water always let the tanks fill before dumping so that no food particles or other residue can accumulate in the tank and deteriorate and smell inside the rig.

I am pretty sure it is the toilet and the (clean) water was running down the outside of the blackwater tank as near as I could tell.If I remove the toilet can I see the pipe where it fits into the top of that tank?

My suggestion is that you fix fresh water leak first and then make sure that it is sewer you are smelling. If you are not sure get an opinion from someone more familiar with rving. It will be easier than trying to fix something that ain't broke.

timdaley wrote:I am pretty sure it is the toilet and the (clean) water was running down the outside of the blackwater tank as near as I could tell.If I remove the toilet can I see the pipe where it fits into the top of that tank?

On my rig the pipe from the toilet leads off at an angle and you could not be able to see how it connects to the black water tank by simply removing the toilet -- maybe different on other rigs. I suspect the type of problem you have will require you to drop the black water tank for inspection - I would give call the mfg or dealer who carries your RV and ask their opinion.

I just installed the 360 vents on my three tank vents (black, grey and kitchen). The upper vent tubes were all stopped up with dirt dauber nests, which caused the foul air to be released inside the trailer rather than out through the vents. Suggest you climb on top, remove the vent caps and peep down with a flashlight to see if the tubes are clear. Something cheap to try!